The Never Ending Debate? Carseats vs. Seatbelts.

The topic of car seats vs. seatbelts surfaces again and again, perhaps for good reason. It arises in the media and in questions from parents on our forums, too. Is it really any safer to restrain my 3-year old in a booster or 5-point harness, rather than just a seatbelt? Do we really need laws to make us restrain our kids with expensive child seats after a year or two? You’d think the answers would be YES. Or NO. But one way or another, we should have proof, right? Apparently, it’s like asking a dozen different Ph.D. Economists which way the stock market is headed, incorrectly assuming there would be a consensus among such brilliant people.

For example, this study holds one opinion (there is also this related published study but the full text is only available for a fee). It is apparently the culmination of a story that appeared in the New York Times, by Freakonomics authors Steven Levitt and Stephen Dubner. In that article, the original authors concluded that for kids 2 and older, “…the ultimate benefit of car seats and booster seats is that they force children to sit still in the back seat. If so, perhaps there is a different contraption that could help accomplish the same goal for roughly the same price: a back-seat DVD player.” The study is compelling. Sadly, this story seemed to be dismissed or ignored by most professional researchers in the child passenger safety field. Maybe this was because it wasn’t published in a peer-reviewed journal for many years and even then in one for economics, rather than medicine or injury prevention. Maybe there is a government/manufacturer conspiracy to foist child seats on us all. Or maybe it was because those researchers didn’t want to acknowledge the truth…

About a year after the New York Times article, one group of researchers finally did bother to respond with a study of their own. This one seemed pretty compelling, too. They even appeared to directly refute the original New York Times article, though perhaps not the updated study linked above [that was published later]. You can also find other studies that measure slightly different things. For example, this study focused solely on 2 and 3 year-olds. Other studies referenced in these articles reach similar conclusions from different methods or sources of data. So, if the average parent reads all of these studies, who do they believe? Even a savvy person with a statistics or scientific background could be confused by these contradicting conclusions that both seem very legitimate. No doubt, there is at least some element of truth in both points of view.

Then there are the laws of physics that [hopefully] are less in doubt. Fatal injuries occur when the body stops moving abruptly. To prevent this, the goal is to couple the passenger to the vehicle as closely as possible by using a restraint system or combination of systems. The better they are coupled, the more likely the passenger is to have a less abrupt stop. This allows the vehicle body to crush and absorb some crash energy in what is called “ride down”. Professional race car drivers know this; they have 5-point harnesses and special helmets, too. On the flip side, lap belts and poorly fitted 3-point lap/shoulder belts on children are notorious for causing serious injury. This is common enough that ER trauma surgeons gave the symptoms a name, “Seatbelt Syndrome“. These injuries are horrendous, sometimes fatal. Suffice to say that you don’t want your child to endure this type of injury.

So the questions-

Are the physics supported by the statistics or not?

If all these authors really had the interest of saving a child’s life, why don’t they get together and figure out the real story?

What do I do for my kid now?

I wish I had answers for the first two questions. I don’t. I hate to think that any of these researchers eschew scientific method and pump out incorrect conclusions in order to further their careers or to sell a few books at the possible expense of a child’s life. I do have an idea about the third question. Misuse is a problem and I wouldn’t argue that it’s easier to misuse a child restraint than it is to misuse a seatbelt alone. On the other hand, as child passenger safety advocates and safety conscious caregivers, we are more likely to properly restrain our kids in their car seats. If we have trouble, we find answers online or take advantage of a trained, local child passenger safety technicianfor help. The result is a carseat that is installed correctly and a child that is properly fitted to the harness or seatbelt system (if using a booster). The statistics in these studies rarely seem to consider proper use. So, what are the odds now for my own properly restrained child, rather than all kids in general?

I have a hunch the odds will be a lot better for my 3-year old in a Britax Boulevard CS or even an inexpensive booster over just a seatbelt, because I am confident I have eliminated the variable of misuse. My older son is almost 10 and still rides in a booster in our minivan, though he does sometimes ride in a lap/shoulder belt in other vehicles. My 7-year old daughter rode in a 5-point harness until last year and is now in a booster. No study I have read indicates that child restraints pose any more risk than seatbelts. So, worst case, perhaps I have wasted countless hours of volunteering and a lot of money on child restraints that will some day prove to be no more effective than just a seatbelt.

Still, I have to wonder about those who make claims against car seats and boosters. Statisticians can put a fixed, monetary price on the cost of a child’s life or serious injury, but do they assign the same value equations to their own children? Do their toddlers and young kids ride in just a lap belt or lap/shoulder belt alone? If not, I suspect they also strongly considered the worst case for their 2 year old in a seatbelt, holding a DVD player in front of them…

excellent post, Darren! You are much more objective regarding some of those studies and articles than I could be. Which is to say, I would have had a hard time referring to DVD player comparison as anything more than utter crap.

You know, both sides seem to have done a lot of work. I hope neither was biased, incompetent, had a hidden agenda or whatever. It just bugs me that the same types of data can be so easily skewed in such different ways. Otherwise, some of the raw data was flawed or someone failed to use scientific method in order to prove their hypothesis correct.

The problem is that we’re not talking about data that shows whether or not home sales and prices will rebound. We’re talking about data that may influence whether or not some parents safely restrain their children to protect them from their #1 killer.

I’d genuinely like to know if I’m wasting all the time, effort and money I’ve invested in child passenger safety. I’m pretty sure I’m not, but there is a little doubt. I’d have no doubt if I found out that the naysayers kept their kids in appropriate child restraints, even if they cite a pesky $50 non-moving citation as their defense!

The authors of Freakonomics have apparently published a new book, SuperFreakonomics, that has more on this topic of boosters vs. seatbelts. I’ve not yet read it, so I can’t comment on whether it is good research or not. Either way, I’m sure it will create a lot of confusion, just as their last one did.

Here are a couple other links with studies that refute their earlier claims:

Who to believe? Well, that is up to the reader, of course. Is there a conspiracy among expert researchers in the medical field and government to foist child seats upon us? Or maybe these economists are hyping their research at the possible expense of the safety of the children of those who buy their books? Again, I wish this issue could be put to rest one way or the other.